The present invention relates to a scanning type atomic force microscope for observing the shape of a surface of a sample as well as a scanning probe microscope for observing the surface physical properties by scanning a probe along the surface of the sample by utilizing a force exerted between substances (that is, a force exerted between the probe and sample).
According to a conventional scanning type atomic force microscope, by using a cantilever formed by silicon nitride or silicon and a stylus formed thereon as a probe for the atomic force microscope, an atomic force exerted between a front end of the stylus and the surface of the sample is detected as a bending movement of the cantilever, a change in an oscillation amplitude or a change in resonance frequency, and the surface of the sample is observed by moving the stylus and the sample relative to each other while controlling a distance between the front end of the stylus and the surface of the sample constant. As another control method, there is a control method of a shear force system where the probe is oscillated horizontally in respect of the surface of the sample. An optical method such as an optical lever method, an optical interference method or the like is mainly used for detecting the displacement of the cantilever. When such an optical method is used, the constitution of the device becomes complicated and adjustment of an optical axis or the like is needed which makes handling of the device complicated.
With respect thereto, a cantilever incorporating a piezoelectric detecting mechanism which electrically detects oscillation has been described in Japanese Unexamined Patent Publication No. JP-A-5-196458 and Japanese Unexamined Patent Publication No. JP-A-6-323845.
Further, a proposal in which a quartz oscillator is used as a probe for an atomic force microscope has been described in Japanese Unexamined Patent Publication No. JP-A-63-309803 and Japanese Unexamined Patent Publication No. JP-A-4-102008.
Further, a method of carrying out nonoptical detection by integrating a tuning fork type quartz oscillator and an optical fiber for constituting a scanning type near-field microscope has been disclosed in Japanese Unexamined Patent Publication No. JP-A-9-89911.
According to each of the detecting methods which do not utilize optical means must integrally form the piezoelectric element and the probe and there poses a problem where even in the case where a portion of the probe is destructed or malfunction is partially caused, a total of the probe must be interchanged. Particularly, in the process of fabricating the probe, when a fixing operation such as adhesion or the like is carried out, there also poses a problem in the reproducibility of dynamic properties.
Further, when static bending of the probe is detected, drift of a base signal included in a static signal is pointed out as a problem in control.
Further, acquisition of function information other than shape information in a nonoptical detecting system is also an important problem.